1. Field of the Invention
The present invention relates generally to a gas appliance, and more particularly to a method of controlling combustion of a gas appliance.
2. Description of the Related Art
Gas appliances, such as water heater, gas stove, and fireplace, are very popular in ordinary home life. For a safety operation, more and more safety apparatus or automatic control systems for the gas appliance are provided in the market to increase the burning efficiency when some problems occurs in the system, such as machine aging, unstable gas supply, and insufficient air.
Liquified petroleum gas is one of the popular gas supplies for the gas appliance. It mainly contains two components, propane and butane. Butane is heavier than propane that butane usually sinks to a bottom of the gas tank. Therefore, the gas appliance burns butane after propane. In other words, the fuel to be burned is different for a full gas tank and a near empty gas tank. However, the conventional gas appliance usually takes the gas in the gas tank is the same that the gas appliance never get its best burning efficiency. For example, some gas appliances take propane for the main fuel to be burned that the burning efficiency will gradually reduce as the gas burned out. It is the same when the gas appliance takes butane for the main fuel to be burned. Therefore, it still has some issues to be improved to increase the burning efficiency of the gas appliances.